The present invention concerns the grounding of a conductive screen to a cathode ray tube (CRT) in a monitor.
An electrostatic field is created outside the face of a CRT by high voltage that is produced by a mask on the CRT's inner face. One method to minimize this electrostatic field includes the application of a conductive coating to the face of a CRT during manufacture. This coating is made part of the ground potential.
Another method to minimize the electrostatic field outside of the face of a CRT is to add on a conductive screen. Such a conductive screen is typically made from a fine mesh conductive material that will pass a high percentage of light. The fine mesh screen is attached to and stretched by a rigid frame. The mesh is attached to the CRT ground potential.
Often the conductive screens are sold separately from a monitor and may be installed by a user. A user mechanically attaches the rigid frame to the bezel of a monitor. The conductive screen is then typically grounded with a wire which is attached to the conductive screen, for example, by solder or epoxy. The other end of the wire is attached by a screw somewhere on the chassis of the CRT. If the wire is short, the wire usually is not attachable unless the bezel is removed. In this case, in order to facilitate attaching the screw to ground, part of the bezel of the monitor needs to be disassembled. When the screw has beem tightened the bezel is reassembled. Disassembly of the bezel may be avoided if the wire is long enough so that it may be attached at the rear of the monitor. In this case, however, a wire may be exposed over a least a part of the lenght of the CRT.